1. Field
The present disclosure relates to a rotor for a rotating electric machine.
2. Description of the Related Art
In related art, as a rotor for use in a rotating electric machine, there exists a rotor having a plurality of permanent magnets arranged in a rotor core at predetermined intervals in the circumferential direction (see, for example, Japanese Patent No. 3746885 and Japanese Unexamined Patent Application Publication No. 2004-194419).
As illustrated in FIG. 10, a rotor 100 described in Japanese Patent No. 3746885 includes a rotor core 101. The rotor core 101 has an inner circumferential portion 103 that surrounds a shaft press-fit hole 102, a plurality of ribs 104 that extend outwards from the inner circumferential portion 103, and an outer circumferential portion 105 that connects the distal ends of the ribs 104.
The plurality of ribs 104 are inclined by a predetermined angle in the circumferential direction, and have a so-called pinwheel configuration. This configuration reduces distortion of the ribs 104 in the axial direction.
As illustrated in FIG. 11, a rotor 221 described in Japanese Unexamined Patent Application Publication No. 2004-194419 has a rotor core 222. The rotor core 222 has an outer circumferential portion 222b, an inner circumferential portion 222c, and a plurality of ribs 222d that connect the outer circumferential portion 222b and the inner circumferential portion 222c. In addition, a rotating shaft 224 is fitted and secured into a shaft hole 222a in the center portion of the rotor core 222, and a plurality of permanent magnets 226 are bonded and secured to the outer circumferential surface.
The plurality of ribs 222d are arranged so as to be inclined at an angle α in directions opposite to each other in the circumferential direction, so that adjacent ribs 222d are symmetrical to each other. By arranging the plurality of ribs 222d in a so-called spoke configuration in this way, the strength of the ribs 222d is improved, and the width of the ribs 222d is reduced (narrowed), thereby reducing the weight of the rotor core 222.